Ensure better hygiene for your cat with our Silica Cat Litter Crystals. We've put all our expertise into developing a cat litter that's been carefully dried to be more absorbent, you'll also notice that it keeps odours away for longer too. This 3.8-litre bag of silica gel quickly absorbs liquids, keeping your cat's litter tray drier and the environment fresher for longer. A 1.7kg accommodates the following usage period: One cat - roughly one month. Two cats - roughly 15 days. Three cats - roughly 9 days. Size: 3.8L.